Dobby drive with shed delaying motion for broad power looms



May 24, 1960 K. METZLER DOBBY DRIVE WITH SHED DELAYING MOTION FOR BROADPOWER LOOMS 3 Sheets-Sheet 1 Filed April 23,, 1956 May 24, 1960 K. METZLER DOBBY DRIVE WITH SHED DELAYING MOTION FOR BROAD POWER LOOIVIS Filed April 23, 1956 I I I I 3 Sheets-Sheet 2 I I I I K. METZLER BOBBY DRIVE WITH SHED DELAYING MOTION FOR BROAD POWER LOOMS 3 Sheets-Sheet 3 Filed April 23, 1956 DOBBY DRIVE WITH SHEDv DELAYING MOTION FOR BROAD POWER LOOMS Kurt Memo, 15 Duwockskamp, Hamburg-Bergedorf,

Germany Filed Apr. 23, 1956, Ser. No. 579,930 Claims-priority, application Germany Feb. 21, 1956 4 Claims. (Cl. 139-66) The invention refers to the drive of dobbies, especially for broad power looms.

As is well known, shedding is done, especially when the so-called closed-shed dobbies are used, by means of dobby knives, driven by the loom shaft by means of a crank wheel, connecting rod, and double gear crank. Such a motion is suflicient for the period of standstill of the shed during shuttle passage, in looms of normal width. In the case of broad looms, however, these means do not sufiice because, owing to the continuous movement, the time of opening of the shed is too short so that the shuttle, towards the end of its course, will be caught and braked by the shed as it closes. To remove these drawbacks, a controlling cam has been put on the driving pinion of the crank pulley on the crank shaft. The application of means of this kind is, however, always limited to certain weaving widths so that in each case the cam must be exchanged by another one having a different curve for a desired delay. Further, these cams will be subject to high wear and tear, especially during the opening of shed when the entire pressure of warp tension will rest on the cam curve.

Moreover, the regulation of an earlier or later shed closing time will be very complicated, as in such a case the whole eccentric motion must be adjusted by means of the screws etc. The new shed delaying motion as hereafter described, represents a solution of the problem, rendering it possible to regulate at will the time of maximum standing still of the shafts according to the width of the loom, and the time needed for passage of the shuttle, this being elfected without having recourse to complicated gear motions by cams etc. Provision has been made to regulate in an easy manner from a central point the earlier or later closing of the shed. The usual drive mechanism for shedding by means of rods is interrupted by an intermediate piston or by an intermediate oscillating lever, both driven by a connecting rod, which is adjustable in length. The shorter this connecting rod is, the greater will be the standing still period of the shafts, whereas a longer connecting rod will mean a shorter standing still period. In the case of particularly broad and heavy-weight looms for weaving the heaviest fabrics, the piston system is preferred, whereas in the case of less heavy fabrics and less heavy looms, the intermediate oscillating lever will sufiice.

The above two solutions by an adjustable connecting rod are hereafter described in order to give a perfect idea of the mechanism.

In the accompanying drawing wherein are shown illustrative embodiments of my invention and wherein only the parts of the loom relating to my invention have been shown,

Fig. I is a side view of the delaying motion, piston system of this invention;

Fig. H is a view from behind (yam-beam side), in the longitudinal direction of the loom of the construction of Fig. I;

ice

Fig. HI is a diagrammatic view showing the mecha-' nism in closed-shed. position;

Fig. IV- is a similar diagrammatic view showing the mechanism in open-shed position;

Fig. V is a graph of the shed movement for the shed delaying motion, taking an average value, the dotted line shows comparatively the curve in the case of normal shedding movement;

Fig. VI is'the side view of a shed delaying motion with intermediate oscillating lever in accordance with the invention;

Fig. VII is a view in longitudinal sense of the .ma-' chine, seen from behind, those machine parts needed to orient the structure being shown in dottedlines;

Fig. VIII is a diagrammatic view of the mechanism of the preceding figures in closed shed position;,and

Fig. .IX is a. similar view in open shed position.

As may be seen from-the view of the closed-shed position, Fig. III, the-adjustable connecting or dobby drive rod 5, the piston or dobby drive rod 7, and the connecting or dobby drive rod 10 are in perfect vertical position.

The open-shed position, Fig. IV, shows clearly how great a standing still of the shafts ST may be obtained with a short connecting or dobby drive rod 5, e.g. nearly a fifth of the circumference. I

The last result is clearly shown by the curve of diagram of shed movement of Fig. V. The curve 21 shows the suflicient time available for shuttle passage at the time of well open shed, in contrast to the dotted curve 22 which shows the movement of shed opening in the case 'of continuous operation.

The loom frame 1 carries the crank shaft 2 on the outer journal of which the drive crank-wheel 3 is fixed. This drive wheel carries the crank pivot 4 for the dobby drive rods which include the connecting rod 5, the control piston 7 and the lifting drive rod 10. The lifting drive rod 10 carries the connecting or drive rod Swhich is joined to the lower part 6 of the control piston 7. The distance between the two points 4 and 6 can be shortened or lengthened according to the desired period of standing still of the shed, by adjusting the right and left-handed threaded intermediate rod of the connecting rod 5. Upon shortening, the standing still period of the shed will be greater, upon lengthening, it will be shorter. The piston 7 is guided during its up and down course in the guide-piece 8. The rod 10 is linked to the top part 9 of the piston 7. Rod 10 is joined in a wellknown way, at point 11, to a universal joint which, at bolt 12 guides the knife crank 15 on knife-shaft 14, thus causing the dobby knives 16 and 17 to oscillate by means of hinge bolts 18 and 19. The rod 10, also with left-hand and right-hand threads at its ends, is adjusted analogously to the adjustment of the connecting rod 5. The earlier or later opening time of the shed will be obtained in well known manner by adjusting the crank pivot 4 in the slot 20 of the crank wheel 3.

Fig. VI shows, in open-shed position, the intermediate oscillating lever 25, carried by loom frame 24 at point 23, whereby the adjustable connecting or dobby drive rod 27 is joined to the oscillating lever 25 at its bottom fulcrum 26 and driven by crank pivot 28 of crank wheel 29 which is secured on crank shaft 30. The top point of the intermediate oscillating lever 25 is connected to the link 32 and 33 and by this to the dobby drive rod 34, which in a usual manner is connected to the double knife-crank 36 at point 37, thus effecting oscillation of the dobby knives 38 and 39 in the slots of dobby frame 40.

I claim:

1. In a closed shed dobby for broad power looms, a driving connection effective to provide a regulation of Patented May 24,19 60- time needed for passage of the shuttle through the shed and keeping said shed open during this time, said driving connection comprising a connecting rod adapted to be selectively shortened and lengthened at will, a drive rod adapted to be selectivelylengthened and shortened correspondingly, a member betweensaid connecting rod and said drive rod and a guide way for slidably receiving said member.

2. In a closed shed dobby for broad power looms, a driving connection eliective to provide a regulation of time needed for passage of the shuttle through the shed and keeping said shed open during this time, said driving connection comprising a connecting rod adapted to be selectively lengthened and shortened at will, a drive rod, and an oscillating lever disposed between the adjustable connecting rod and the drive rod for transmitting the drive movement.

3. In a closed shed dobby for broad power looms, a driving connection effective to provide a regulation of time needed for passage of the shuttle through the shed and keeping said shed open during this time, said driving connection comprising a connecting rod of variable length, a drive crank wheel to which said rod is pivoted at one end, a control piston pivotally connected at one end to the other end of said rod, a guide way slidably receiving said piston and a drive rod pivotally connected to the other end of said piston.

4. In a closed shed dobby for broad power looms, a driving connection elfective to provide a regulation of time needed for passage of the shuttle through the shed and keeping said shed open during this time, said driving connection comprising a connecting rod of variable length, an oscillating lever pivotally connected to one end of said rod, an intermediate link also pivotally connected at one end to said lever, and a drive rod pivotally connected tothe other end of said link.

References Cited in the file of this patent UNITED STATES PATENTS 1,853,985 Lindsjo Apr. 12, 1932 1,944,369 Randall Jan. 23, 1934 2,613,693 Jarvis Oct. 14, 1952 FOREIGN PATENTS 439,705 Great Britain Dec. 12, 1935 

